About medicine

What is medicine?

Medicine is the science and practice aimed at understanding and maintaining human health, and at preventing, diagnosing and treating disease and relieving suffering when cure is not possible.

The World Health Organization's constitution defines health as a state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity — a definition that makes the aim of medicine wider than treating diseased organs.

Four questions medicine works on

How does the body work?

• Anatomy, physiology, cells and genes — the starting point of the Human Body section.

What happened?

• Diagnosis: gathering the medical history, examination, tests and imaging to arrive at an explanation.

What do we do?

• Treatment: lifestyle, medicines, procedures, surgery and rehabilitation.

How do we prevent it?

• Prevention: vaccines, early detection and reducing risk factors.

How does medicine know?

Evidence-based medicine means combining the best available research evidence with the doctor's expertise and the patient's values and preferences. The doctor's experience alone is not enough, and neither is a single study.

Not all evidence is equal: a large randomised trial is usually stronger than an observational study, and a systematic review of several trials is stronger than a single trial. For this reason the treatment and prevention sections on this platform carry an "evidence strength" badge following the GRADE approach.

Correlation is not causation: if a study finds that two groups differ in a disease, this does not necessarily mean that the difference between them is the cause of the disease.

What medicine does not know yet

Many medical questions have incomplete answers. For this reason, each page here separates what is established, what is under investigation and what is early research, and states clearly when the evidence is insufficient.

Where next?

• The journey of medicine
• Medicine today
• The human body
• Editorial method